Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
  • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
  • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
  • G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
  • G01D5/145—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the relative movement between the Hall device and magnetic fields
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D3/00—Indicating or recording apparatus with provision for the special purposes referred to in the subgroups
  • G01D3/028—Indicating or recording apparatus with provision for the special purposes referred to in the subgroups mitigating undesired influences, e.g. temperature, pressure
  • G01D3/032—Indicating or recording apparatus with provision for the special purposes referred to in the subgroups mitigating undesired influences, e.g. temperature, pressure affecting incoming signal, e.g. by averaging; gating undesired signals

Definitions

• the present invention relates to a process for compensating the temperature of the measurement carried out by a magnetic sensor, in particular a magnetoresistive sensor, this sensor being influenced by a magnetic field placed on a turntable or recti line with cyclic movement.
• magnetic sensors are those sensors that deliver a variable output signal with the magnetic field they undergo.
• the magnetic field in turn can be a field whose variation is linked to an external parameter, so that the sensor can deliver a signal dependent on this external parameter and reflecting the variations.
• the magnetic field can depend on the position of a permanent magnet or an electromagnet and the sensor will deliver a signal whose value will depend precisely on this position.
• the Hall sensor or the magneto-resistive sensor, which delivers an electrical signal
• the method can be applied, mutato mutandis, with any type of magnetic / analog sensors.
• this type of sensor has a linearity zone, that is to say a zone where the signal delivered varies linearly with the quantity to be measured.
• the present invention aims precisely to compensate in temperature the measurement carried out by a magnetic sensor, by mechanical means only, without using any compensation electronics. This compensation is obtained according to the invention when the measured magnetic field is seen cyclically by the sensor.
• the signals delivered by the sensor are made two by two and consecutively, respectively when it is subjected to the magnetic field to be measured and by this same sensor when it is subjected to a reference magnetic field; this ratio K below reflecting the measurement is independent of the temperature variations, the two signals varying in the same proportions as a function of the temperature.
• the magnetic sensor is a magneto-resistive sensor which delivers variable electrical signals in response to variations in magnetic fields and the reference magnetic field generator is a permanent magnet.
• the senor is placed so that it passes in front of the generator of the magnetic field to be measured and behind the reference magnetic generator, or vice versa, so as to alternate the polarities of the signals alternately. delivered by this sensor, relative to a zero line.
• the intensity of the signals delivered by the sensor is then measured at the peak using a blocker and, for reasons of convenience and reliability, the value of "zero" of the sensor is located, corresponding to the absence of signal, to a non-zero value.
• This value is for example represented by a positive voltage, which makes it possible to place all the variations of the signal in the positive range.
• FIG. 1 is an illustration of the signal delivered by the sensor alternately passing in front of the magnetic field i that to be measured, then in front of a reference magnet
• - Figure 2 corresponds to Figure 1, the sensor being located in an environment whose temperature is higher than that of figure 1,
• FIG. 3 corresponds to FIG. 1, the sensor being placed at the same temperature, but undergoing a different magnetic field and,
• FIG. 1 is an illustration of the embodiment in which the polarity of the signals is reversed, which is a convenient means of differentiating the measurement M of the reference signal R.
• the variable field emitter and the magnet reference are arranged on a turntable which, as illustrated, are offset by a half turn.
• the offset can be chosen arbitrarily, of any value, the signals M and R no longer being equidistant in time, which flows from left to right.
• the value of the magnetic field acting on the sensor is represented by H, by K the ratio of the peak intensities of the measurements M and of reference R, as quantified at peak using a blocker.
• the temperature prevailing around the sensor is T 1 and the two + signs, indicated on either side of the "zero" line are simply intended to indicate that this zero value is not zero, but located at positive voltage .
• the actual electrical zero is located in the lower left corner of the figure.
• the temperature has no influence on the measurement K carried out by the sensor
• the measurement K carried out by the sensor reflects the variation of another parameter, in this case the variation of the magnetic field.
• this type of sensor operates in a very wide range of temperatures, for example in its linearity zone, in particular in - 40 ° C and 150 ° C.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Measuring Magnetic Variables (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)
• Measuring Temperature Or Quantity Of Heat (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9334558

Family Applications (1)

Country Status (9)

Families Citing this family (2)

Citations (2)

• 1986
  • 1986-04-21 FR FR8605915A patent/FR2597592A1/fr not_active Withdrawn
• 1987
  • 1987-04-16 BR BR8707678A patent/BR8707678A/pt unknown
  • 1987-04-16 JP JP62502536A patent/JPH01502294A/ja active Pending
  • 1987-04-16 DE DE8787902545T patent/DE3767489D1/de not_active Expired - Lifetime
  • 1987-04-16 EP EP87902545A patent/EP0303609B1/fr not_active Expired - Lifetime
  • 1987-04-16 AT AT87902545T patent/ATE60129T1/de not_active IP Right Cessation
  • 1987-04-16 WO PCT/FR1987/000124 patent/WO1987006688A1/fr active IP Right Grant
  • 1987-04-21 ZA ZA872786A patent/ZA872786B/xx unknown
  • 1987-04-21 ES ES8701415A patent/ES2003309A6/es not_active Expired

Patent Citations (2)

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